Images that are captured using a camera generally have several kinds of problems. For example, if the camera is not properly white-balanced, images tend to have a red or blue cast. If there is insufficient lighting in the scene, images tend to be dark and show little contrast. Also, if light reflects off objects in the scene, other objects tend to have a color cast associated with the reflected light.
As another example, modern cameras often have automatic systems for estimating the proper exposure. However, these systems are sometimes fooled due to the lighting conditions or atypical characteristics of the scene being captured. In addition, modern cameras, as well as their predecessors, often allow the photographer to manually adjust the exposure setting, thereby introducing the possibility of human error.
These and other color problems are commonly fixed using image correction tools that run on a computer workstation such as a PC (personal computer). These tools allow a user to select one or more image processing functions to apply to an image and to adjust parameters of these functions. Currently available image correction tools are powerful, but tend to have a steep learning curve.
To reduce the learning curve and the time required to manipulate the image processing functions, automatic tools for image correction are available. Such tools analyze an image and adjust parameters of an image correction operation to improve the color, exposure (i.e., brightness level and contrast), and other parameters in the image. Examples of such tools include the Photoshop™ and Photoshop Elements™ software from Adobe Systems Incorporated. Functionalities of such tools may also be incorporated into other products that include a large suite of service offerings including, for example, Microsoft Windows Live™ and iPhoto™ from Apple.
Image correcting tools can often be operated in one of two different modes. In the first mode, the tools that implement these corrective measures can be manual in that, for example, a user views the image on a computer screen and employs a user interface to interactively adjust the color and/or exposure. In the second mode, the tools provide for automatic correction of color and/or exposure in an image. In these systems, a user typically accesses the image, which can be viewed on a computer screen, and activates an automatic correction program. This activation can be implicit, in the sense that the automatic correction program is called whenever the image is accessed; it can also be explicit, in which case the user clicks on a button to call the correction program when necessary.
Several current image tools include user interfaces which display a choice of corrections that may applied to an image in which various parameters are varied and shown in image previews (i.e., what the image would look like once the correction is applied). While current tools can often provide satisfactory results in some applications, the variations in corrections provided by the tools are usually based on limited information—the variations are applied to vary color or exposure simply by applying steps that are shown in multiple previews. One preview is a little lighter, another is a little darker, another preview is a little more blue, etc. However, such variations do not use any kind of deterministic methodology to understand how a user may behave or what the user's intentions may include, when determining and providing the choices of corrections that may be applied to a given image.
As a result of the inherent nature of many image correcting tools, automatic image correction can sometimes produce incorrect results because, for instance, of a failure to recognize the effect or result that the photographer intended to achieve. For example, when the exposure of an image is automatically corrected, an incorrect result may occur if the photographer intended to present a foreground object in silhouette. In this case, automatic image correction is likely to brighten the foreground object in an attempt to correct for the lack of a fill flash. Unfortunately, this automatic exposure correction is essentially the opposite of what the photographer desired. In addition to exposure corrections, other types of automatic image corrections can suffer from similar problems.
This Background is provided to introduce a brief context for the Summary and Detailed Description that follow. This Background is not intended to be an aid in determining the scope of the claimed subject matter nor be viewed as limiting the claimed subject matter to implementations that solve any or all of the disadvantages or problems presented above.